<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        span{
            width: 0;
            height: 0;
            display: block;
            border: 10px solid transparent;
            border-top-color: #333333;
        }
    </style>
</head>
<body>
<span></span>
</body>
</html>